System information

Troubleshooting IBM 10-219
Local SRB: Host Cannot Connect to Server
Hop count exceeded Use the show protocol route command to check the hop count values on routers and
bridges in the path. Packets that exceed the hop count are dropped.
Alternatively, you can enable the debug source event privileged exec command to see
whether packets are being dropped because the hop count has been exceeded.
Caution: Because debugging output is assigned high priority in the CPU process, it can
render the system unusable. For this reason, use debug commands only to troubleshoot
specific problems or during troubleshooting sessions with Cisco technical support staff.
Moreover, it is best to use debug commands during periods of lower network traffic and
fewer users. Debugging during these periods decreases the likelihood that increased
debug command processing overhead will affect system use.
Increase the hop count if it is less than the default value, 7. Otherwise, the network must
be redesigned so that no destination is more than 7 hops away.
Router is not
configured to forward
spanning explorers
Spanning explorer packets are equivalent to a single-route broadcast. Routers must
therefore be configured to route them.
Step 1 Use the show source-bridge exec command to determine whether the
spanning explorer count is incrementing.
Step 2 If the spanning explorer count is not incrementing, use the show
running-config privileged exec command on routers to see whether the
source-bridge spanning interface configuration command is configured. This
command configures the router to forward spanning explorers.
Step 3 If the command entry is not present in the configuration, add it to any router
that is required to pass spanning explorers. The command syntax is as follows:
source-bridge spanning bridge-group[path-costpath-cost]
Syntax Description:
• bridge-group—Number in the range 1 to 9 that you choose to refer to a
particular group of bridged interfaces.
• path-cost—(Optional) Path cost for a specified interface.
• path-cost—(Optional) Path cost for the interface. The valid range is 0 to
65535.
Example:
The following example adds Token Ring 0 to bridge group 1 and assigns a
path cost of 12 to Token Ring 0:
interface tokenring 0
source-bridge spanning 1 path-cost 12
Step 4
Use the show source-bridge exec command to determine whether explorers
are being sent.
Step 5 If explorers are not being sent, place a network analyzer on the same ring to
which the end system is connected.
Step 6 If you find spanning all-ring frames, use the show running-config privileged
exec command to make sure the router is properly configured. If sessions still
cannot be established over the SRB, contact your technical support
representative for more assistance.
1 Although you can enter the ring number in hexadecimal or decimal, it always appears in the configuration as a decimal number.
2 FDDI = Fiber Distributed Data Interface
3 PVC= permanent virtual circuit
4 RIF = routing information field
5 MAC = Media Access Control
Possible Problem Solution